The effects of ZnSe quantum dot (Qd) concentration on the fluorescence in Poly(3-hexylthiophene-2,5-diyl) matrix (P3HT) are investigated. The fluorescence spectra were found to be very dependant on the Qd concentration and light emission is significantly enhanced by incorporation of ZnSe Qd in the polymer matrix. Using a theoretical model for hybrid (organic–inorganic) system, interesting numerical results for the light emission and relative quantum efficiency as a function of ZnSe Qd concentration were obtained. The theoretical results were found to be in good agreement with experimental data.